Computing devices, such as notebook computers, personal data assistants (PDAs), and mobile handsets, have user interface devices, which are also known as human interface device (HID). One user interface device that has become more common is a touch-sensor pad. A basic notebook touch-sensor pad emulates the function of a personal computer (PC) mouse. A touch-sensor pad is typically embedded into a PC notebook for built-in portability. A touch-sensor pad replicates mouse x/y movement by using two defined axes which contain a collection of sensor elements that detect the position of a conductive object, such as finger. Mouse right/left button clicks can be replicated by two mechanical buttons, located in the vicinity of the touchpad, or by tapping commands on the touch-sensor pad itself. The touch-sensor pad provides a user interface device for performing such functions as positioning a cursor, or selecting an item on a display. These touch-sensor pads can include multi-dimensional sensor arrays. The sensor array may be one dimensional, detecting movement in one axis. The sensor array may also be two dimensional, detecting movements in two axes.
FIG. 1A illustrates a conventional touch sensing slider that is mapped to a set of characters. The touch-sensor slider pad 100 includes a sensing surface 101 on which a conductive object may be used to contact the sensing surface 101 to cause a mapped character 102 associated with the position of contact to be outputted to a display device (not shown). Touch-sensor slider pad 100 maps each output character to a resolution range 103 of the touchpad. A resolution range is defined as the slider resolution divided by the number of characters mapped to the slider. In the illustration of FIG. 1A, the resolution range for each character would be 10.
However, in order to provide more output options, conventional systems map additional characters 154 to a touch-sensor slider pad 150. FIG. 1B illustrates a touch-sensor slider pad 150 mapped to twice the number of output character 154. Assuming the resolution of touch-sensor slider pad 150 is the same as touch-sensor slider pad 100, the resultant resolution range per character is divided in half. Due to uncertain pressure of a conductive object, small movements of a conductive object and the compacted resolution range for each character, the precision of output characters cannot be ensured.